I had the good fortune recently to meet John Tilleman and Corey Goerdt, two young entrepreneurs who hope to uplift the world's poorest people with a new twist on a cheap yet powerful technology: solar cookers. They were among about 15 teams who competed for the grand prize in the University of Washington Foster School of Business' Global Social Entrepreneurship Competition (GSEC), which is marking its fifth year.

Tilleman already wowed the judges in a similar competition last year in London, winning nearly $40,000 in prize money in the Big Idea competition sponsored by the Chartered Insurance Institute.

Solar cookers aren't a new idea. Some 3 billion people around the world still rely on using wood, dung or other biomass as fuel for cooking. Plenty of people (even folks in sun-deprived Seattle!) have been working to develop an efficient, affordable solar cooker because of the harmful effects of this primitive technology to both people and the environment: Smoke inhalation from burning wood and other biomass causes indoor air pollution that experts blame for more than 1 million premature deaths annually. The demand for wood promotes deforestation, and the smoke and soot from the fires is a potent contributor to climate change.

Tilleman, who became involved in Engineers Without Borders' chapter at Brown University, had a eureka moment after visiting Tanzania in January 2008. He developed a way to manufacture an ultra-cheap solar reflective material from recycled plastic shopping bags (the kind of bags that the City of Seattle may start taxing to discourage their use).

According to Tilleman, the process involves melting the plastic shopping bags into a thick layer of plastic and then adding a layer of reflective plastic, like the kind inside bags of potato chips (a staple food of college students). When exposed to sunlight, the material gets very hot and can heat up a pot or pipes containing water. Voila! Germs terminated.

It would be a miracle if solar cookers could make a dent in the devastating toll of diarrheal illnesses on children. An affordable technology is desperately needed in many countries where water-sanitation technologies such as chlorination and filtration systems are too expensive. While solar disinfection may not be possible in places that get sun only sporadically, the potential for impact is tantalizing in tropical climates. Solar ovens require little if any training to operate and solar irradiation has been shown to reduce diarrheal disease by as much as 26 percent, according to the World Health Organization.

Goerdt suggested to me that they could hitch a ride on the microcredit craze and sell the solar cookers at cost to female Tanzanian entrepreneurs who would resell them to villagers at a small profit. What better way to promote local adoption than having locals who know the culture sell the product? In this way, the solar cooker could be a triple threat -- to disease, deforestation and diminished economic opportunities for women.

I'm cheering on these young entrepreneurs. If you know of similarly low-tech or high-tech applications that have global health implications, send me an email. Here's a 90-second video excerpt of my interview with the pair after they presented their business plan to judges at the GSEC competition.




SolarCycle in 90 Seconds from Sanjay Bhatt on Vimeo.